Converter for direct-current generators



Dec. 25, 1923.

M. J. HOCKLEY CONVERTER FOR DIRECT CURRENT GENERATORS Filed April 7. 1923 IN VEN TOR.

f/oolley Patented Dec. 25, 1923.

UNITED STATES 1,478,518 PATENT OFFICE.

MARION JAY HOCKLEY, OF RIDGWAY, COLORADO, ASSIGNOR 0F ONE-HALF TO FRED- ERICK BERGNER, 0F

RIDGWAY, COLORADO.

Application filed April 7, 1923.

To all whom it may concern:

Be it known that I, MARION JAY HooKLnY, a citizen of the United States, residing at Ridgway, in the county of Ouray and State of Colorado, have invented certain new and useful Improvements in Converters for Direct-Current Generators, of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to electric generators, and particularly to means whereby direct current may be converted into alternatin current.

Cue of the objects of my invention is to secure any desired frequency or alternation without running the direct current generator at a greater speed than the normal speed for which it is designed and without altering the generator in any way.

A further object is to provide a device of this character which will also act as a frequency changer.

'Another object is to provide a converter which is independent of the armature from which the current is received.

Still another object is to provide a converter of this character which is very simple, which may be readily applied to any direct current generator, and in which the number of segments to be used may be readily changed. 7

Other objects will appear in the course of the following description.

My invention is i lustrated in the accompanying drawings, wherein Figure 1 is a perspective view of a conventional or standard direct current generator showing my improvement applied thereto;

Figure 2 is a diagrammatic projection of the periphery of the auxiliary commutator, ShOWiIlg the arrangement of the segments:

Figure 3 is a diagrammatic perspective view showing the manner in which the current travels when the brushes all engage the se ments 10;

igure 4 is a diagrammatic perspective view showing the manner in which the current travels when the brushes are in engagement with the sections 11", 11", 11 and 11;

Figure 5 is a diagrammatic perspective view of a modification of the segments, showing the manner in which the current travels when the brushes engage with four separate segments;

Serial No. 630,547.

Figure 6 is a diagrammatic perspective view of the same arrangement of segments, showing the manner in which the current travels when the brushes are in engagement with two segments.

By referring to the drawings, it will be seen that my converter comprises in effect a commutator which is mounted upon the shaft of a direct current generator and rotates therewith, the armature being provided with two parallel series of segments, the segments of one series being separated from each other by insulating material and all of the segments of one series being separated from all of the segments of the other series by insulating material, each series of segments consisting of pairs of relatively short segments with relatively long segments interposed between the short segments, the two ad acent pairs of short segments being connected by crossed conductors and there being four brushes used, two of the brushes being connected to the line and two to the terminals of the generator.

In the drawings, A designates a direct current generator of any usual or suitable character and having a shaft B, the plus terminal C, and the minus terminal D. Mounted upon the shaft B to rotate therewith is a commutator E made up of two circumferentially extending series of conducting segments, the segments being disposed side by side. Certain of these segments are relatively long and are designated 10, and between these two relatively long segments in both series are disposed the four short segments 11", 11", 11 and 11. The two series of segments are separated from each other by a circumferentially extending layer of non-conducting material 12 and adjacent segments are separated from each other by transversely extending pieces of non-conducting material 13. Thus each segment is entirely insulated from any other segment and from the frame supporting the sections. The insulating material may be of horn, fiber or mica. The segments will be of com mutator copper. The segments are held in place between pressure plates 14 of any usual or suitable construction so formed as to hold the segments and the insulation firmly in place. The commutator so formed has a central bore by which it may be slipped upon the shaft B and ma be held on this shaft to rotate therewith in any suitable manner as, for instance, it may be keyed on the shaft by means of a key 2').

Coacting with the segments are four brushes 15, 15, 15 and 15 These brushes are supported upon a bracket 16 which is bolted to the end yoke of the generator, the bracket having an opening through which the shaft B passes and having a horizontal flange 17 which supports the several brushes. The brush 15 is connected to the minus dynamo terminal 18, while the brush 15 is connected to the plus dynamo terminal 18.

It will be seen from Figure 2 that the segments 11, 11", 11 and V 11 are relatively short so that a forward pair of brushes and a rearward pair of brushes cannot be upon a pair of segments at the same time, the total length of the two pairs. of segments, how? ever, being such that when the forward pair of brushes is engaged with the forward pair of segments as, for instance, 11 and 11, the rear pair of brushes l5 and 15 willbe upon the segments 11, and 11 Thesegments 10, however, are of such length that both pairs of brushes may engage these segments at the same time, as in Figure 8. e V V The operation of the mechanism so far as described is as follows: When both pairs of brushes rest upon the segments 10, as illustrated in Figure 3, current will enter the brush 15 from the positive pole of the generator, thence pass along the segment 10 to the brush 15, then pass through the line wire 19 to the brush 15, thence along the corresponding segment 10 to the brush 15 and thence to the negative pole of the generator. l Vhen the brushes, however, have passed the segments 10 and engage the seg ments 11 11", 11 and 11 as illustrated in Figure at, the current will be reversed and will pass from the generator to the brush 15, to the segment 11*, thence by way of the crossed conductor 20 to the second segment 11 then through the brush 15 to the line wire 19, thence through this wire to the brush 15, thence by the crossed connection 20 to the segment 11*, thence to the brush 15 and thence to the negative pole of the generator. It will thus be seen that the direct current will be converted into alternating current.

It will be seen that with this construction used, for instance, wit-h a bipolar generator wherein the armature speed is four, my commut-ator revolving at the same speed and having four segments would produce two cycles per revolution, or in four revolutions would produce eight cycles, and it will fur: thermore be noted that it is possible to get any number of cycles desired by placing any number of segments on the commutator in pairs, one pair for each cycle, namely one pair of straight segments and two pairs of transposition segments 11?, 11", 11 and 11, each pair when brought under the four stationary brushes producing one cycle. With my device it is possible to get the desired number of cycles without running the gem erator at a speed above its normal and without in any way altering the generator. It will be seen that my commutator is very simple and may be readily applied to any direct current generator. If a bipolar generator is used, the greatest frequency it is possible to secure by the application of slip rings is one cycle per revolution, but with my invention it is obviously possible to secure any desired frequency per revolution without changing the generator at all or operating the dynamo at above its normal armature speed. My commutator is independent of the armature and depends wholly on the regulation of the generator to which it is applied for its output.

It will be understood that the mechanism might be changed in many respects without departing from the spirit of the invention and that I do not wish to be limited to any particular details of construction except as defined in the appended claims.

I claim p 1. The combination with a direct current generator having an armature and having positive and negative terminals, of a commutator rota-ting with the armature and formed to provide parallel pairs of insulated long and short segments and two pairs of brushes engaging the face of the commutator, the long segment having a length equal to the circumferential distance between the brushes, the pairs of long segments being disposed in alternating relation'to two pairs of shortsegments, each of the short segments being less than the distance between the brushes and each of the short segments being electrically connected to the diagonally related short segment, two of the brushes be ing electrically connected respectively to the positive and negative terminals and the other two brushes being connected to the line. Y r

2. The combination with a direct current generator having an armature and having positive and negative terminals, of a commutator rotatable with the armature and formed to provide parallel pairs of insulated long and short segments and two pairs of brushes, the short segments having a length less than the distance between the brushes and the long segments having a length greater than the distance between the brushes, the brushes of one pair being electrically connected to the positive and negative terminals of the generator and the? other pair of brushes being connected to the line, the short segments of the commutator being electrically connected to the diagonally opposite adjacent segment whereby to alternate the direction ofv current in the line 3. A converting current direction commutator adapted to be disposed on the armature of a direct current enerator, said commutator having pairs 0 insulated long and short segments and two pairs of brushes, the short segments having a length less than the distance between the brushes and the long segn'ients having a length greater than the distance between the brushes, the brushes of one pair being adapted to be electrically connected to the positive and negative poles respectively of the generator and the other pair of brushes being adapted to be connected to the line, the short segments of the commutator being electrically connected to the diagonally opposite adjacent segment whereby to alternate the direction of current in the line.

In testimony whereof I hereunto aflix my signature.

MARION JAY HOCKLEY. 

